What is Mil-spec & 550 Paracord?

Parachute cord (also paracord or 550 cord) is a lightweight nylon kernmantle rope originally used in the suspension lines of US parachutes during World War II. Once in the field, paratroopers found this cord useful for many other tasks. It is now used as a general purpose utility cord by both military personnel and civilians. This versatile cord was even used by astronauts during STS-82, the eighty-second Space Shuttle mission, to repair the Hubble Space Telescope.

The braided sheath has a high number of interwoven strands for its size, giving it a relatively smooth texture. The all-nylon construction makes paracord fairly elastic; depending on the application this can be either an asset or a liability.While the U.S. military has no overall diameter requirements in its specifications, in the field 550 cord typically measures 5⁄32 inches (4 mm) in diameter.

Types

US Military issue paracord is specified by MIL-C-5040H in six types: I, IA, II, IIA, III, IV. Types IA and IIA are composed solely of a sheath without a core. Type III, a type commonly found in use, is nominally rated with a minimum breaking strength of 550 pounds, thus the sobriquet "550 cord".[citation needed]The US military specification for paracord outlines a number of parameters to which the final product must conform. Although it contains specific denier figures for the sheath strands and inner yarns, there are no overall diameter requirements for the cord itself.